Railway traffic controlling apparatus



, June 6, 1944. v. P. SHEPARDS ON 2,350,699

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed June 25, 1943 @{T 2 r 5L m 1%) v0 b, 0 J 4 013 I Q5565 v I I QINVVENTOR I ne P. Slzqna drazz 'HIS ATTORNEY Patented June '6, 1944 RAILWAY TRAFFIC CONTROLLING APPARATUS. o

Vene P. Shepardson, ,Belview Heights, Ala., as- I signer to The Union Switch and Signal Coin pany', Swissvale, 3a., a corporation of Pennsyl Vania ,ApplicationJune 2? 1943.;Seiial 5, 49 ,3 9

10mins. (-'c1.2 4

My invention relates to railway .trafiic. controlling apparatus, and particularly to apparatus for efiecting control of an approach indication device in a given direction over a pair of conductors, that is, from a given end of a pair of conductors to the other, and for then efifecting control of a signal in the opposite direction over the same pair of conductors. I

In interlocking plantsof either the manually controlled type orthe automatically controlled type, -it has been common practice to control approach "indication relays over given line conductors and to control the corresponding distant signals over difierent line conductors or over the-track rails. l One feature of. my invention is the'provision of an' approach indication circuit normally. energized over the railsof the track section into which a distant signal governs traific movements, and the provision of a circuit which can become energized either" manually or automatically over the-rails of the same track section for clearing the distant signal after the approach indication circuit becomes deenergized by a train approaching'the distant signal.

I shalldescribe two forms of apparatus embodying my invention, and shall then point out the novel features thereof in claims. In the accompanying drawing, Fig, l'isa diagrammatic view showing one form of apparatus embodying my invention in which a two-indication signal iscontrolled by a neutral circuit ;and Fig. 2 is a diagrammatic View showing a modified form of the apparatus of Fig. 1 in' which polarized control of a three-indication signal is provided. n

Similar reference characters refer to similar parts in each of the views.

Referring first to Fig. 1, a stretch of railway track is shown,'over which traffic movements are normally made in the direction indicated by the arrow, which I shall assume is the eastbound direction." This stretch of track is divided by insulated joints 2 into'section OIT, IDT and IT. Each of the sections OIT and .IT is provided with a track circuit including a suitable source of current, such as a, battery 3, connected across the rails adjacent one end of the section, and a track relay, designated by the reference character-R with a distinguishingprefix'corresponding to the prefix for the reference character T for the same track section, connected across the rails adjacent the opposite end of the section.

I A home signal I is shown adjacent the entrance end of section IT for governing trafilc greener proceed 'lamp-G anda red orstop lamp R. Signal ID is also ofthe two-indication color light type, comprising a green or proceed lamp G andayellow; or caution lamp Y. These signals may, however, be of any othersuitable type. Section OlTserves as an approach section for signal ID, and track relay QIR may therefore be termed an approachedrelay...

An approach controlrelay-AR-is normally ene gized by.,a,circuit including front contacts of approachrelay-OIR, and -;including,the rails of tracksection IDT,; and alsoiincluding back cone tacts oiaghome signal relay [H which controls signal].

.-O nly portions of twocontrol' circuits for, relay IH are shown, one of whichincludes a back contact of relay AR, and the other of which includes a normallyopen contact M of a manual control lever V, and bothof which include contact I5 of track relay,- IR, Lever V has a normal position 1;, in which; itis shown in thedrawing, and a reverse position r to which it ismoved to close contact ltl.

Relay II-1,, upon becoming energized by either of these con trol circuits, closes its contacts 1 and; 8 at their front. points, and hence a distant signal relay IDH-,for controlling signal ID, will become energized over a circuit including the rails of section ID 'I -if relay' OIR is deenergized, or when it becomes deenergized dueto the presence of a train on section OIT. I I

' An approach indication device, here shown asa lamp AK, is-controlled by'a back contact of ream I i In Fig. 2, the apparatus differs from that shown inFigL, 1 in'the control'of signal ID which is here athree-indication signal. Relay IDH is here a polarized relay controlled by circuits of normal and reverse polarities,Yeachincluding the rails of ec n m 11'? 5 With relay 1| H deenergized, relay IDH can become energized by its reverse control circuit which includes back contacts of 'eachbfthe relaysfAR lH. and OIR... An asymmetric unit if, whichfcan ,be of 'the -well known copper oxide half-wave rectifier type, opposes'the flow of current frornithis'r'everse control circuit through relay AR, thereby preventing energization of relay AR by the reverse control circuit for relay. IDH. The normal control circuit for relay IDH includes front points of contacts I and 8 of relay IH, 'which' tlie'rebyserve as pole changeraand the back points ,ofIconta-cts of relay OIR. As'shownin the drawing,all parts are in the normal conditionfthatis, lamp' R of signal I is lighted, andfthelamps of signal ID are unlighted; relays OIR,lR;' and 'AR'are energized; relays JH and lDHare deenergiz'edflever v is in its normal P sition 11 and indication lamp is 'unlighted.

I shall now describeymore in detail, the operation of the apparatus shown in Fig: 12'" .The cir cuit by which relay AR is normally energized passes from a source of current, such as a bat tery 4, through the front point. ofcontactj of 1;

relay OIR, rail 6 of section IDT, the back point,

of contact I of relay IH, winding of relay AR, v

back point of contact 8 of relay ilH ,;rai1; 9 of 5, 1

section IDT, and the frontpointof contact l0.

of relay OIR back to battry d; The circuit by which lamp R of signal I is lighted passes from terminal B, through the back-pointer contactll of relay IH, and lamp R to terminal 0.

I shall assume that an eastbound train enters f the back point ofcontact 13- of relay-AR, and

contact 15 otrelay -I'R-. Relay lH, uponbecoming energized, opens, -a't the back point- 0fits contact I I, the circuit previously traced for lamp R of signal -I, and closes,'at the-front point of contact-l l,

signal I.

-With relay lI-I energized and relay OlRdeenergizedya circuit-is completed for energizing relay IDH, this circuit passing from a suitable I source of current such as'a battery l6-,'through the front point of contact 1 ofrelay'lI-Lrail 6 of section IDT, back point of contact 5 of relay OIR, winding of relay IDH', back point of contact IQ of relay OIR, rail 9 of section lD'I', and the front point of contact 8 of" relay I I-I back to battery I6; With relay IDH now energized while relay O-lR-isdeenergized, a circuit is completed for lighting lamp G-of' signal ID, this circuit passing from terminalB, through 'contact I! of relay OIR, front point-of contact l8 of relay iDI-I, and lamp G of signal'lD toterminalO.

When the train enters section IDI, thecircuit previously traced for relay IDH will be shunted by the wheels andaxlesof the trainacross rails 6 and 9 of section-lDTyand hencerelay IDH will become deenergized, causing lamp G tobecome extinguished, and causing lamp Y tobecome lighted by a circuitpassingfro'rnv terminal B, through contact I! of relay 0IR', back"point of contact l8 of'relay l'Dl Land lamp Y'ofsignal lD to terminal 0,

When the train leaves section OIT, contact I! of relay OIR open, thereby extinguishing lamp Y of signallD. Relay OIR, upon becoming energized, closes'its contacts 5 and; ID at their front points, as in theno'rmal condition of the apparatus.

The train, .upon'entering section IT, willdeenergize relay |R, c0ntact 15, of which will thereupon open the circuit for relay, IH, .Larnp R. of signal I will therefore again become lighted When the train leaves section IDT, thereby removing the shunt fromjrails 6 and 9' of section IDT, vrelayAR will become-energized:- by its circuit, previously] traced, Indication, lamp AK willtherefore becomeextinguished.

Inthe form of apparatus shownin Fig. 2, the

the circuibfonlighting lamp G-of Fig. .1,-except that it includes the asymmetric unit t in its low resistance direction.

With the apparatus shown in Fig. 2, I shall assume that a train enters section OIT, there- ID will therefore be lighted by a circuit passing.

from-terminal B, through contact I! of relay OIR,-back point of contact I8 of relay IDH, and lamp R'of signal ID to terminal 0. With relay 'OIR deenergized, the circuit for relay AR will be disconnected from'battery 4 at contacts 5 and i0 of,relay OIR, and hence relay AR will become deenergized.

If section IT is noW occupied, or if relay IH cannot become energized for some other reason, relay. IDH will. now become energized in thereverse direction by a circuit passing frombattery I6,'through contact 20 of relay AR, backpoint of contact 8 of relay IH, rail fl of sectionlDT,

while a train occupies section OlT, relay lDH will-become energized in the normal direction by a circuitv passing from battery l6; through the front point ofv contact I of relay lH, rail 6 of section IDT, back, point of contact 5 of relay OIR, winding of relay IDH, back point of, contact l0v of relay OIR, rail 9 of section IDT, and the fr nt point of contact 8 of relay: l H back to battery It. With relay IDH energized; by current of normal polarity, lamp G of signal; lD-will become lighted bya circuit passing from terminal B, through contact ll of relay OIR, front point of contact [8 of relay lDH,.co ntact l 9lof relay IDH closed; in the left-hand position; and lamp G of signal ID .to terminalO.

When the train enters section IDT,-thereby shunting the circuit -for;relay IDH at rails i and 9 of section JD'I, relay- IDH. will become deenergized, thereupon again-completing the circuit previously traced for lamp R of signal ID.

When the train leavessection IDT, relay AR will again become energized by its circuit including asymmetric unit if.

Although I have herein shown and described only two forms of apparatus embodying myin vention, it is understood that various changes and modifications may be made thereinwithin the scope of the appended. claims without departing from thespirit andscopeof my invention.

Having thus described my invention, what-I claim is:

1. In, control means for a home signal and for a distant signal for said home signal, includinga track; section between said home and distant signals,includingvan approach track relayi'orian approach track section which adjoins said? first track. section. at a point adjacentsaid distant signal,,,including. a signal relay for controlling said circuit by which relay AR is no'rmallyenergized v is the same as was traced in connection with 75' home signal, the combinationlcomprising an. ap,- proach control relay, a track circuit including th rails ofsaid track section between said home-and distant 'signalsand inclu ing front and backcon-r tactsofJsaidIapproachttrack relay and said signal relay respectively for controlling said approach control relay, a back contact of said approach control relay included in a circuit for controlling said signal relay, a distant relay for controlling said distant signal, and a circuit including the rails of said track section between said home and distant signals and including front and back contacts of said signal relay and said approach track relay respectively for controlling said distant relay.

2. In an approach indication and signal control scheme for a given signal including a first track section into which trafilc movements are governed by said given signal, including an approach track section through which traffic movements are made before passing said signal into said first section, including a normally energized approach relay which becomes deenergized in response to a train entering said approach track section, and including a signal relay for controlling said signal, the combination comprising, a manually controllable relay, an approach indication device, a circuit including the rails of said first track section and controlled by a front contact of said approach relay and by a back contact of said manually controllable relay for controlling said approach indication device, and a second circuit including the rails of said first track section and controlled by a back contact of said approach relay and by a front contact of said manually controllable relay for controlling said signal relay.

3. In an approach indication and signal control scheme for a given signal including a first track section into which traffic movements are governed by said given signal, including an approach track section through which traffic movements are made before passing said signal into said first section, including a normally energized approach relay which becomes deenergized in response to a train entering said approach track section, and including a signal relay for controlling said signal, the combination comprising, an approach control relay, a second signal relay controlled in part by a back contact of said approach control relay, a circuit including the rails of said first track section and controlled by a front contact of said approach relay and by a back contact of said second signal relay for controlling said approach control relay, and a second circuit including the rails of said first track section and controlled by a back contact of said approach relay and by a front contact of said second signal relay for controlling said first signal relay.

4. In an approach indication and signal control scheme for a given signal including a first track section into which traffic movements are governed by said given signal, including an approach track section through which traffic movements are made before passing said signal into said first section,

including a normally energized approach relay which becomes deenergized in response to a train entering said approach track section, and including a signal relay and means for at times energizing said signal relay, the combination comprising, an approach indication device, a circuit controlled by a front contact of said approach relay and by a back contact of said signal relay for controlling said approach indication device, and a second circuit controlled by a back contact of said approach relay and by a front contact of said signal I relay for controlling said signal.

5. In an approach indication and signal control scheme for a given signal including a first track section into which trafiic movements are governed by said given signal, including an approach track section through which trafiic movements are made before passing said signal into said first section, including a normally energized approach relay which becomes deenergized in response to a train entering said approach track section, and including a signal relay and means for at times energizing said signal relay, the combination comprising, an approach indication device, a circuit controlled by traffic conditions in said first track section and by a front contact of said approach relay and also by aback contact of said signal relay for controlling said approach indication device, and a second circuit controlled by traffic conditions in said first track section and by a back contact of said approach relay and by a front contact of said signal relay for controlling said signal.

6. In an approach indication and signal control scheme for a given signal including a first track section into which traffic movements are governed by said given signal, including an approach track section through which traffic movements are made before passing said signal into said first section, including a normally energized approach relay which becomes deenergized in response to a train entering said approach track section, including a signal relay and means for at times energizing said signal relay, and including an indication relay and indication means controlled by said indication relay, the combination comprising, an asymmetric unit, a circuit including said asymmetric unit and the rails of said first track section and controlled by a front contact of said approach relay and by a back contact of said signal relay for controlling said indication relay, a circuit of a given polarity opposed by said asymmetric unit including the rails of said first track section and controlled by a back contact of each of said relays for controlling said signal, and a circuit of the opposite polarity including the rails of said first track section and controlled by a back contact of said approach relay and by a front contact of said signal relay for also controlling said signal.

7. In a circuit arrangement for controlling a given neutral relay at a given point by current supplied over a given pair of conductors from a remote point and for controlling apparatus at the remote point by current of normal and reverse polarities supplied over 'the same pair of conductors from said given point, the combination comprising, an asymmetric unit, a pole changer at said given point arranged to be closed in a first or a second position, a control contact at said remote point arranged to be closed in a first or a second position, a circuit including said asymmetric unit and said pair of conductors and including said contact and said pole changer in said first positions for energizing said neutral relay, a circuit of a given polarity opposed by said asymmetric unit including said pair of conductors and including said control contact in its second position and said pole changer in its first position and controlled by a back contact of said neutral relay for controlling said apparatus at said remote point, and a circuit of the opposite polarity including said pair of conductors and including said control contact and said pole changer both in their second positions for also controlling said apparatus at said remote point.

VENE P. SI-IEPARDSON. 

